#define _CRT_SECURE_NO_WARNINGS 520
#include<stdio.h>

int my_strlen(char* arr)
{
	int count = 0;
	while (*arr++ != '\0')
	{
		count++;
	}
	return count;
}



int main()
{
	char arr[] = "hello world";
	int len = my_strlen(arr);
	printf("%d", len);
	return 0;
}